Grass Tetany in Beef Cattle

Grass tetany is a nutritional disorder resulting from inadequate blood levels of magnesium
(Mg). Conditions which increase the risk of this problem include lush,
rapidly growing grass pastures, prolonged cloudy weather, older cows in
early lactation that are heavy milkers, and soils that are low in Mg and
calcium (Ca) and high in available potassium (K).

Pasture fertility plays a role in this problem. Phosphorus fertilization of low
Pcontaining soils has been shown to increase Mg content of tall fescue
forage.Research has also shown that pastures fertilized with high levels of
K and nitrogen (N) can cause a disruption of Mg absorption in grazing
livestock. A balanced pasture fertility program based on soil test
recommendations should eliminate these issues.

Grass tetany most often affects cattle in late gestation or early lactation, especially
the heaviest milking cows. Older animals are more susceptible to grass
tetany than younger animals because they cannot mobilize
bone Mg as efficiently as younger animals when dietary supplies are
inadequate. Additionally, older animals are generally harder to keep in good
body condition which also contributes to this metabolic problem. You should
give a little extra care to older, thinner animals this time of year in
relation to preventing grass tetany.

Prevention is the best treatment and is most easily accomplished by providing Mg in a free
choice, loose mineral supplement. Dry cows should consume 10 grams of Mg per
day, while cows nursing calves should consume 20 to 25 grams of Mg daily.
Mg supplements are not very palatable and Mg is quickly cleared from the
blood, so it is important that animals consume Mg daily.

In order to provide this amount, a commercial mineral mix containing at least 10 percent
Mg is recommended. Other mixes can be made on-farm using a variety of feed
and mineral ingredients. Feeding hay containing red clover or alfalfa is
also beneficial, because legumes contain about twice as much Mg as grasses.

For more information on grass tetany or on Mg containing supplements, contact your
local MU Livestock Specialist.

Vegetable Garden Fertilization: Nitrogen May Be All You Need

An article based on a recent survey by University of Missouri soil test laboratory verified a trend
specialists reviewing soil test results have noticed -that
most vegetable garden's soil test results show that soil phosphorus (P) and
potassium (K) as very high, and soil pHs high. (see Soil Test Summary for
Urban Lawns and Garden Soils, Missouri Environment and Garden, January 2010)

Why has this occurred?

For P and K, most likely because vegetable gardeners have the tendency to seasonally or
annually apply 'balanced fertilizers', those that have nitrogen (N), P and
K. While the N is quite mobile, leached by water or volatilized to the
atmosphere, P and K adhere to the soil tightly, thus they 'build up'.
Use of organic fertilizers (e.g. manure or compost) won't change a build up
from occurring, as most organic fertilizers are balanced as well.

While the nature of some soils to have a high pH, usually due to significant amounts of calcium
carbonate in the underlying rock, the survey revealed the situation
too widespread and common for this to be the main factor. Over application
of lime, or other alkaline materials like wood ashes, is the likely culprit.

What should a vegetable gardener do?

Have your soil tested, and then focus on only supplying the needed nutrients, and
increasing organic matter if less than 5 percent. For established vegetable
gardens where nutrients have built up, the focus may be on just one nutrient,
nitrogen!

Easily found synthetic choices of N without any P or K for home garden use are few- urea
(46-0-0) and ammonium sulfate (21-0-0). Ammonium sulfate is a good choice
when soil pH is very high or high, as the sulfur will gradually reduce the
soil pH. Calcium nitrate (15.5-0-0) can be found, but it is a specialty
product targeting greenhouse and hydroponic markets, where the 19% supply of
calcium is desired.

Synthetic fertilizers
that are slow or time release aredesired by many gardeners, as they are
less likely to 'burn' plant tissue (either roots or foliage). Some
specialty turf products are now available with only N. However,balanced
formulations are more common. An option is to select slow or time release
fertilizers that are highest for 'N' and lowest in 'P & K'. Often, these
fertilizers are marketed for turf applications.
Formulas in the range of '22-5-6' and '25-2-5' are available.

For organic fertilizers, there are several options. First, if you have the time, grow a
legume cover crop and till it under about a week or two before planting.
Legumes fix N with the root nodules and it is accumulated in the green
growth, which when plowed down is sometimes referred to as 'green manure',
in reference to its fertility. Good sources of N organic fertilizers without
P or K are corn gluten (9-0-0), blood meal (13-0-0), and feather meal
(12-0-0). There are other balanced organic fertilizers high in N like
soybean and cottonseed meal (7-2-2). Organic fertilizers vary in how quickly
the N is available, from slow to medium. Only fish emulsion (4-2-2) is
considered 'fast'. The MU Guide 6220 'Organic Gardening Techniques' is a
good source of information on organic fertilizers frequently used
by gardeners (http://extension.missouri.edu/publications/DisplayPub.aspx?P=G6220).

Spotted Knapweed

Spotted knapweed (SK) has not officially been located in
central Missouri but it has been found in the countiesbordering Audrain,
Benton and Chariton Counties. Only Audrain has an infestation near enough to
possibly be an immediate problem. Still as a noxious weed in Missouri, it is
a plant to watch.

A native to Europe, SK was introduced to the U.S. in the late
1800's. It was first recognized in southwest Missouri in 2002. It is now
found throughout southwest andsouth-central Missouri mostly south of
I-44. It has also been found in multi-county areas in east-central
andnorth-central Missouri.

As a short-lived perennial, SK is a thistle like plant
forming a rosette the first year and grows a 2-4 foot tall flowering stalk
the second year. The pale green leaves are rather sparse on the woody
flowering stems. Flowers are pink to purple in color and buds are about
3/4-inch long.

A characteristic making SK especially noxious is a
toxin produced by the roots that kills or suppresses nearby plants. This is
called allelopathy.

Seeds are the sole means of reproduction. It is a prolific
annual seed producer, with 1000 or more seeds per plant. Once established,
seeds accumulate in the soil, often exceeding 5000 per square foot and
remain viable for at least eight years.

Landowners are advised to be watchful for spotted knapweed,
and keep it in check while it is only along roads and not out in pastures.
If not controlled, it can rapidly invade pastures and fields and causes a
serious decline in forage and crop production. As a weed listed in
Missouri's noxious weed law, landowners can be compelled to attempt control.

Several herbicides are effective at controlling SK when used in a timely manner. In order of effectiveness are:

Milestone at a 5 to 7 ounce per acre rate (based on plant size)

Tordon 22K at 1 pint per acre (restricted-use herbicide)

Grazon P+D at 4pints per acre (restricted-use herbicide)

They are best applied at the bud stage in the spring or at the rosette stage in the fall.

Once the plant blooms, herbicides are rather ineffective. Blooming plants should be pulled
and burned. Anyone handling SK is advised to wear gloves to avoid
skin irritation.

There is some good news connected with the control of SK. Biological controls were begun in
2008 and expanded in 2009. This involved the release of two host-specific
weevils. They are the SK seedhead weevil and SK root borer weevil. Also, the
knapweed seedhead fly is already present in Missouri.

It will take several years for populations of these insects to grow large enough to begin
providing significant control of the SK.

A similar weed biological control project against muskthistle in Missouri with two weevils
was a huge success. Large populations of musk thistle were knocked back in
southern Missouri and kept from spreading north.

In an effort to help farmers move toward more energy efficient and profitable operations, the
Missouri Department of Natural Resources' Energy Center has developed
a $3 million energy efficiency cost-share grant program under Energize Missouri Agriculture.

The department is offering the energy efficiency cost-share grants to
agricultural operations statewide for agricultural energy efficiency
improvements and renewable energy equipment. The program offers cost-share
grants to farm operators, owners or renters. The energy
efficiencycost-share grant program reimburses farmers up to 75 percent of
the purchase cost of qualifying energy efficient equipment and systems, up
to $5,000 per applicant.

Items eligible for reimbursement include purchased energy efficient equipment and hardware, but
do not include time and labor spent installing or operating the equipment.
The Energy Center has identified equipment and systems that qualify for
funding however; the department is also looking for new and innovative
technologies that can be applied to agricultural energy efficiency.

Upgrade or new grain dryers (both burner and fan retrofit for existing systems or total new systems).

Lighting upgrades, motion sensors or timers (retrofit of entire lighting system in an existing building).

Conservation tillage equipment.

High efficiency electric motors.

Biomass furnaces/boilers for other than poultry houses.

For other energy savings projects to be considered, one would
provide a short narrative describing your proposed project, including cost,
estimated energy savings per year, documentation/calculations for estimate,
payback in years and type of equipment you intend to purchase as part of the
application process.

An application form is also available at all local County
Soil and Water District offices or by contacting the department's Energy
Center at 573-526-1723. The approved paper form is the only hard copy that
will be accepted. Please do not print out the electronic version for use as
a hard copy submission. Application forms must be post marked and mailed to
the department or sent electronically through the web site by April 20, 2010.

Funding for the agricultural energy efficient cost share
program is provided by the U.S. Department of Energy through the American
Recovery and Reinvestment Act. For more information, contact the Energy
Center at 800-361-4827 or 573-751-3443, visit the local Soil and Water
Conservation District office, or visit the Missouri Department of Natural
Resources' Energy Center's Web page at:
www.dnr.mo.gov/transform/EnergizeMissouriAgriculture

Did you Know?

The most powerful earthquake to strike the United States occurred in 1811, centered in New Madrid,
Missouri. The quake shook more than one million square miles, and was felt as far as
1,000 miles away.

Ag Connection is published monthly for Central Missouri Region producers and is supported by University of Missouri Extension, the Commercial Agriculture program, the Missouri Agricultural Experiment Station and the MU College of Agriculture, Food and Natural Resources. Managing Editor: Kent Shannon.